Apparatus for curing tobacco



Feb. 1, 1966 R. D. TouToN APPARATUS FOR CURING TOBACCO Filed Dec. 13, 1961 INVENTOR. RUSH D. TouToN BY 5%.. Mig

ATTORNEYS FIG. 2.

y Rush D. Tonton, Wynnewood, Pa,

United States Patenti() `3,231,935 APRARA'IUS FR CURING TOBACCO Wurton Machine Company, 9th and Columbia Sts., Philadelphia, Pa.) Y

Filed Dee. `13, 1961, Ser. No. 159,111

4 Ciai'ms. (31. 341-219) This invention relates to apparatus forcurinjg tobacco yand more particularly relates Ito `fapparatus which ad- Vantageously takes advantage of solar heat and/or nocturnal radiation.

It is known to be highly advantageous to cure Vtobacco in compact 'beds formed by hanging the tobacco closely spaced to Jform such beds. Heretoiore, in carrying out such curing it has been necessary to employ full-time, costly airconditioning equipment in order to provide conditioning Vair at the desired temperature; Further, conventional air con-ditioning apparatus has heretofore been required in order to prevent condensation on the tobacco during so-'called rest periods when the temperature of the conditioned air `is lowered, it being recognized recently that intermittent rest periods are advantageous in curing tobacco to a high quality. i

Unexpectedly in accordance with th-is invention, it has been found that highly vetiicien-t and very economic apparatus can be provided largely eliminating eonventional .air conditioning devices and relying forthe necessary heat and .air movement mainly on solar heat energy and nocturnal radiation.

The invention will be understood fnom a reading of the following description in conjunction with the drawings in which:

FIGURE 1 is .a ver-tical section .of 'appal'atus in accordance with this invention taken by the line 1-1 in FIGURE 2; and

FIGURE 2 is a horizontal section of the `apparatus of FIGURE l taken on the plane indicated by the line 2-2 in FIGURE l. y

As shown in the iiguresa housing 2 has a concrete slab foundation 4 on whichupright posts 6, 8, 10, 12, 1d 4and 16 are supported. It is desirable to have the foundation 4 slope towards the front or rear, for example, a 2 slope downwardly from 'left to right as viewed in FIGURE 1. A joist 1S is supported by posts 6 .and 12, the 4latter post being .shorter than the former to provide for the sloping of the joists from left to right .as viewed 'in FIGURE `-l at an angle of about lto the horizontal. Advantageously the slope of the joists will be rin the range of from 5 to 20 below the horizontal. A secondwjoist, not shown, is similarly supported by posts l8 and 1h.

The housing 2 iii PIzQYdd With an outer front wall 2d,

outer side wal-ls 22 and 24 and an outer rear wall 26. Housing 2 is located with wall 24 facing in a southerly direction, preferably a little west of south, such :as 190. An inner front Wall 28, inner side walls 3l? and 32 and an inner rear wall 34 are .also provided, upright members 36, 38, 4l) and 42 .being provided for the purpose of securing the inner front panel V28 and the inner rear panel 34. insulating material 46 fills the spaces between the inner and outer walls. Any su-itable insulating material such `as, for example, rock wool :or spun glass or reilec` tive sheets such as aluminum sheets, may be employed. A door 48 hinged as indicated at 50 and having a securing latch 52 and a handle 54 is installed in the rear of the housing 2. As shown in FIGURE 1, the door is formed yof ya front panel S6, alrear` panel S8 between which is placed insulation 69. The right-hand end of housing 2, as viewed in FIGURE `1, is provided with a vent opening 62 controlled by .a door I64 hinged at `66, the interior of door 64 is also `filled with insulating material indicated at 68. An exhaust lblower 69 `at opening `62 is desirable.

on theplrane indicated ICC Blowers 6'9 are mounted 4in housing 70 which is open at its lower end 7l. y

A plurality of transverse beams '72 vare supported in cutout portions 74 of the joists. Flat sheets 76 of, for example, plywood :are secured to the beams 72 and to the joists. In turn the sheets 76 fare overlaid with a black sur.- faciog material 3l), which may be, for example, black rooting paper, pitch or lblacl: paint. The pit-ch of the plane in which sheets 76 lie is approximately 10 below the horizontal and Aadvantageously wil-l be in the range of `from 5 to 20 below the horizontal. Black corrugated iron, where :snow Vand ice loads permit, may be substituted for sheets '76 and black surfacing material Sti.

A curing chamber 82 is formed within housing 2 by partition @d land -ceiling 86, which is substantially parallel to sheets 76. Ceiling 86 has a depending flange indicated zat 88 and rests on the upper ends ot outer wall 24, inner wall 32. As will be seen from FIGURE l, sheet 76 and ceiling S6 form, in etiect, .a duct open to the atmosphere at its right-hand end 4and discharging into the interior of housing 2 at its leftehand end.

Partition 84 has an `opening 92 rat its lower end controlled by door 94 .pivoted =at 96, .a latch 98 being provided to hold the door in open position when so desired. Partition 84, together with walls V28, 39 .and 34, forms in effect an air duct .adjacent curing chamber 82 which leads from the lower portion of curing chamber 82 to the upper portion of chamber 82, partition 8d having an opening 100 .at its upper end. A flapper Valve 102 hinged at 104 is providedto control the ilow of air into the upper portion of curing chamber 82. The position of -iapper valve 162 is controlled by a line 1% secured to valve 1li?. =at 10S extendingupwardlythroughthe root` .and over pulleys 1 1@ and 11,2. Line 1% has a counter-balancing weight 114- secu-,red to it :to provi-de for ready adjustment of valve 102 and to maintain valve 102 in `a desired posit-ion.

Blowers 118 mounted on transverse beam 120 `are provided to pull air through opening la@ into curing charnber 32.

'l`o provide for the hanging of strung tobacco, curing chamber 82 is provided with beams 124.- which are substantially parallel to foundation d to which are secured closely :spa-ced'liooks 126 which are adapted to support strings 128 carrying `the tobacco 13h. As is known in the art, a tightly packed bed of tobacco can be formed also y by supporting the butt ends of the tobacco leaves on a screen.

A door 134 hinged at 136 is provided between beams 124- to provide a supplemental inlet or outlet as to utilize fog without rain and a vent opening at night to achieve a chimney effect.

A burner is supported on foundation 4. Burner 140 has a pilot light 14,2 which burns continuously.

Operation In operating the above described apparatus of this invention, the strung tobacco of, for example typical cigar leaf, will be placed in chamber 52 with advantageously from about `60 to 300 leaves per square toot. When the temperature of the outside air is higher than the bed ternperature which generally occurs at about ten oclock in the morning, apper valve 1M will be approximately horizontal to permit the ilow ot air exterior housing 2 into curing chamber d2. The air exterior the housing will have been somewhat heated by the sun and will be substantially further heated during its passage between roofing sheet 76 and ceiling 86, beams 72 providing some turbulence in the air flow which further facilitates the heating. While not essential, it is desirable to have a black surface on sheets 76 in order to increase the heating effect by the sun. The heated air tending to move upwardly will move from right to lett as viewed in FIG- URE 1 to the area adjacent opening 100 where it will be drawn into chamber 82 by blowers 118, and forced downwardly through the bed of tobacco. Depending upon the air conditions desired in the tobacco bed, the air can be partially recirculated passing rst through opening 92, then back into chamber S2 through opening 100 and partially exhausted through vent opening 62, or all of the air can be exhausted through vent opening 62 by closing door 94. It is desirable to prevent the temperature of the air passing through the tobacco bed from exceeding a desired maximum usually in the range of 100 F. to 120 F. at the time it is introduced to the bed. Flapper valve 102 is moved upwardly as necessary to prevent excessive het air from being introduced into the chamber 82. Further lowering of the temperature of the air supplied to the tobacco bed can be achieved by opening of door 134.

When the air temperature drops to about 5 F. above the temperature or" the tobacco bed, which is generally about 6 pm., blowers 118 are stopped, and door 94 closed with valve 102 in the horizontal position. As the outside air cools down to a temperature below the temperature of the tobacco bed, the ow of air reverses and air gradually moves upwardly through the tobacco bed. Due to radiation from the roof, there is a substantial cooling efect on the air in the duct above ceiling S6 causing air to flow downwardly in the duct to the outside of the housing 2 thus also acting as a reversed chimney and creating a negative pressure over the tobacco bed. In addition, if desired, door 134 may be lett open during this period for the exhaustion to the atmosphere of the warm air moving up from the top of the bed.

This reverse ow of air at night prevents any damaging build up or localized centers of moisture which would harm the tobacco. The upward ow of air through the tobacco bed is aided by the heat stored by the tobacco. This air movement is increased by the employment of slab foundation 4 which acts as a heat bank gradually giving up heat during the night. A slab foundation, however, is not essential. Door 64 will be ajar during this period and will be regulated so as to prevent the tobacco bed temperature from being lowered to the temperature of the outside air to prevent moisture condensation on the tobacco.

When the heat supplied by the sun has been low for a prolonged period it may be desirable to expedite curing to supply heat from the burner in the daytime.

The next morning the cycle of procedures is repeated and is continued from day to day until the tobacco is in a satisfactory cured condition as is evidenced to an expert in the eld by the color and moisture content of the tobacco.

The operation of blowers 69 while not essential, may be employed to provide close humidity control and/or a more uniform flow of hot air downwardly through the bed by increasing the negative pressure under the front end of the bed which is remote from the point where the hot air first is introduced above the bed. It is to be noted that reasonably good distribution of air through the bed is achieved by the gradually reducing transverse vertical cross-sectional area about the tobacco bed from left to right as viewed in FGURE 1.

What is claimed is:

1. Apparatus for curing tobacco leaves comprising walls, a floor and a sloping ceiling forming a chamber, a heat conducting sloping roof spaced above said ceiling and together with the ceiling forming an air duct for conveying air from the surrounding atmosphere at a point adjacent the lower point of the ceiling to discharge it at a point adjacent the upper end of the ceiling when the roof is being heated by the sun and in turn the roof is heating the air in the duct during the daytime and for conveying air from a point adjacent the upper end of the ceiling downwardly to the exterior of the apparatus when the roof is cooling the air in the air duct during the nighttime, means for supporting a compact bed of tobacco intermediate the top and bottom of said chamber, means operable to draw air discharging at a point adjacent the upper end of the ceiling into said chamber and pass it downwardly through said tobacco bed and means for connecting the lower portion of said chamber to the atmosphere whereby heated air is passed downwardly through the tobacco bed to heat and cure the tobacco when the roof is heated and air passes upwardly through the heated tobacco bed when the roof is cooling the air in the air duct due to the heating of air by the tobacco bed and due to radiation causing air to ilow downwardly in the duct to the exterior of the apparatus, the last mentioned flow of air causing a negative pressure over the tobacco bed.

2. Apparatus in accordance with claim 1 in which the oor is a concrete slab, the slab being heated by the air flowing downwardly through the tobacco bed and giving up heat when the air reverses its direction of ilow to flow upwardly through the bed.

3. Apparatus in accordance with claim 1 in which the floor is a concrete slab which slopes downwardly towards the means for connecting the lower portion of the chamber to the atmosphere, the slab being heated by the air flowing downwardly through the tobacco bed and giving up heat when the air reverses its direction of tlow to flow upwardly through the bed.

4. Apparatus in accordance with claim 1 in which the means for connecting the lower portion of the chamber to the atmosphere includes a blower adapted to withdraw air from the chamber and discharge it to the atmosphere.

References Cited by the Examiner WILLIAM F. ODEA, Primary Examiner.

NORMAN YUDKOFF, PERCY L. PATRICK,

Examiners.

I. P. ROBINSON, I. SOFER, Assistant Examiners. 

1. APPARATUS FOR CURING TOBACCO LEAVES COMPRISING WALLS, A FLOOR AND A SLOPING CEILING FORMING A CHAMBER, A HEAT CONDUCTING SLOPING ROOF SPACED ABOVE SAID CEILING AND TOGETHER WITH THE CEILING FORMING AN AIR DUCT FOR CONVEYING AIR FROM THE SURROUNDING ATMOSPHERE AT A POINT ADJACENT THE LOWER POINT OF THE CEILING TO DISCHARGE IT AT A POINT ADJACENT THE UPPER END OF THE CEILING WHEN THE ROOF IS BEING HEATED BY THE SUN AND IN TURN THE ROOF IS HEATING THE AIR OF THE DUCT DURING THE DAYTIME AND FOR CONVEYING AIR FROM A POINT ADJACENT THE UPPER END OF THE CEILING DOWNWARDLY TO THE EXTERIOR OF THE APPARATUS WHEN THE ROOF IS COOLING THE AIR IN THE AIR DUCT DURING THE NIGHTTIME, MEANS FOR SUPPORTING A COMPACT BED OF TOBACCO INTERMEDIATE THE TOP AND BOTTOM OF SAID CHAMBER, MEANS OPERABLE TO DRAW AIR DISCHARGING AT A POINT ADJACENT THE UPPER END OF THE CEILING INTO SAID CHAMBER AND PASS IT DOWNWARDLY THROUGH SAID TOBACCO BED AND MEANS FOR CONNECTING THE LOWER PORTON OF SAID CHAMBER TO THE ATMOSPHERE WHEREBY HEATED AIR IS PASSED DOWNWARDLY THROUGH THE TOBACCO BED TO HEAT AND CURE THE TOBACCO WHEN THE ROOF IS HEATED AND AIR PASSES UPWARDLY THROUGH THE HEATED TOBACCO BED WHEN THE ROOF IS COOLING THE AIR IN THE AIR DUCT DUE TO THE HEATING OF AIR BY TOBACCO BED AND DUE TO RADIATION CAUSING AIR TO FLOW DOWNWARDLY IN THE DUCT TO THE EXTERIOR OF THE APPARATUS, THE LAST MENTIONED FLOW OF AIR CAUSING A NEGATIVE PRESSURE OVER THE TOBACCO BED. 